Apparatus for preparing laminated articles



Sept. 21, 1943. wHlTEHEAD 2,329,867

APPARATUS FOR PREPARING LAMINATED ARTICLES Filed Dec. 2, 1941 Patented Sept. 21,

APPARATUS FOR PREPARING LAMINATED ARTICLES Ned-Whitehead, Los Angeles, Calif. Application December 2, 1941, Serial No. 421,319

2 Claims.

This invention relates to the manufacture of identification cards and the like, consisting of an opaque lamination of paper or the like, carrying identifying matter, incased between laminations of transparent plastic material, such as cellulose acetate. 7 v

An object of the invention is to facilitate, and reduce the cost of making laminated articles of the type referred to.-

A more specific object is to increase the effective capacity of a press employed to seal together the laminations of articles of the type referred to.

It is quite common practice today to imbed identification cards and the like between sheets of transparent plastic material inorder to afford mechanical protection to the identification cards and also make it more difiicult to alter or forge such cards. Various well-known plastic materials are in use for this purpose, and generally the sealing operation is effected by first heating and then cooling'the assembled elements of the card .while they are tightly pressed together.

A card of conventional size, say 2.5 x 3.75 inches requires a pressure of the order of 10,000 pounds, necessitating the use of relatively heavy presses which are expensive. The eifective work capacity of a press is determined by the length oftime that the cards must be left therein. Obviously, if the cards need be left in the press only a short time, a small press can handle as much work as a much larger press, in which the cards have to be left for a long time. It has heretofore been the practice to employ presses adapted to be first heated, and then cooled while the work is contained therein. Obviously, each cycle of operation requires a considerable period of time.

In accordance with the present invention, I have discovered that the working capacity of a press of given size can be greatly increased by providing holding means for holding the cards under compression after they have once been compressed in the press. By this expedient, the cards can be removed from the press much more quickly than formerly, because they are cooled exterior of the press. Furthermore, the press can be kept hot all the time. When the cards have cooled they can be removed from the holders by repressing them in a second inexpensive, unheated press to enable the removal of the holding means therefrom.

My invention also contemplates the complete elimination of a heated press by first compressing the cards in a cold press and locking them under compression in holding devices which are then removed from the press. Thereafter the cards, while compressed in the holding devices, are placed in a suitable oven and left to cure, after which they are removed from the oven and released from the holding devices. The oven may be of the continuous type in which the cards are progressively moved through a heating zone to cure them and then through a cooling zone to cool them.

Other more specific objects and features of the invention than those enumerated will become apparent from the detailed description to follow of a particular embodiment of the invention.

In the drawing:

Fig. 1 is a face view of an identification card of the type to which the present invention relates;

Fig. 2 is an exploded view showing the elements of an identification card and a holding unit for holding the card elements together during the curing operation;

Fig. 3 is a plan view looking down on the top of the assembly shown in Fig. 2;

Fig. 4 is an elevation view of a press that may be employed in connection with the invention, showing a device in accordance with the invention positioned therein;

Fig. 5 is a perspective view, showing the parts of Fig. 2 assembled together and maintained in compression by the retaining clips; and

Fig. 6 is a cross section of the card shown in Fig. 1 the section being taken on the line VI-VI of Fig 1. Referring to Figs. 1 and 6, there is shown a completed identification card which consists of an inner sheet of paper Ill enclosed between laminations Il-ll of plastic material such as cellulose acetate. It will be observed from Fig. 6 that at the edges of the card the plastic laminations II have become fused together to form a continuous integral coating completely enclosing the card "I. The card I0, of course, bears any desired information, which may consist of printing, writing, photographs, etc., the actual subject matter being immaterial in connection with the present invention. i

As is observable from Fig. 2, the laminations ll of plastic material are originally separate sheets between which the card I0 is positioned. Thereafter, the sheets Hll are compressed against the card l0, and against each other at the edges, by high pressure with the application of heat, which causes the plastic sheets II to bond with the card I over its surface, and bond with each other beyond the margins oi the card.

The present invention has to do with the bonding operation.

Thus, in accordance with the invention, a card I 0 is assembled between the sheets ll of plastic material and'then the assembly is positioned within a holding unit designated generally by the reference numeral i2 and consisting of a pair of pad members 83 which are, in turn, positioned between pressure plates l4. Each of the pressure plates 14 has secured to its outer face. by a rivet IS, a bowed spring plate It.

The parts are first assembled with the card in, the plastic sheets i l, the pad members i3 and the pressure plates lying flat against each other, and are inserted between the pressure faces ll of a suitable press 18 (Fig. 4) while the press is in open position. At this time the spring plates l6 are outwardly bowed from their associated pressure plates H, as shown in Fig. 2; Thereupon the press is closed with suflicient force to flatten the spring plates l6 flat against the pressure plates- M, as shown in Fig. 4. The

unit I2 is then locked in compressed position by slipping U-clips l9 over the opposite ends of the unit 12, so that they engage the ends of the spring plates l6 and hold them together after the press is opened. I

The press may be of any desired type provided the pressure faces I! are so dimensioned as to permit application of the clips i 9 while the 'unit 12 is in the press.

The particular press disclosed in Fig. 4 comprises an upper, stationary pressure member 20 supported above a base 2| by vertical standards 22, and a lower, movable pressure member 23 which is guidingly supported for vertical movement on the standards 22 and is movable upwardly by a hydraulic ram 24 actuated by a pumping handle 25. The ram 24' may be identical to an ordinary hydraulic jack and need.not be further described herein.

As shown in Fig, 4, the pressure members 20 and 23 of the press are adapted to be electrically heated and to this end are provided with conventional heating elements, not shown, adapted to be supplied with heating current through an electric cord 26 which enters the upper pressure member". A second cord 21., extending from the upper member 20 to the lower member 23, supplies current to the latter. The electric heating elements may be thermostatically controlled to maintain a desired temperature, but the particular type of heating element employed, or the particular temperature employed, is not relevant to the present invention, which resides in the clamping assembly l2 and methods of curing that are made possible thereby.

One procedure in accordance with the invention is to clamp a card to be sealed within the assembly l2, as described, in a hot press. such as the press 18 in Fig. 4, leave the assembly in the press for a short time suflicient to heat the card, then remove the assembly l2 containing the card while still retained in compressed condition by the clips i9, as shown in Fig. 5, and permit it to cool, after which the assembly is reinserted in a. press to relieve the force on the clips I9, which are removed; then the press is opened and the finished card removed from the assembly i2. This procedure effects substantial economies in press equipment because as soon as each of the units 12 is removed from the hot Another procedure in accordance with the invention is to initially compress the assembly i2 in a cold press for attachment of the retaining clips l8, and thereafter place the compressed assemblies 12 in any suitable oven for curing. This greatly increases the capacity of a single press, since assemblies can be inserted in and removed from the press substantially as fast as it can be closed and opened.

Although I have shown in Fig. 4 a press adapted to receive only one of the units l2 at a time, obviously the size of the press can be increased to compress a plurality of units simultaneously,

if so desired, so long as the pressure faces of the thick and each of the laminations i i is'approximately .015 inch thick.

Each pad member l3 may consist of a layer of blotting paper l3a approximately one-sixteenth of an inch thick and secured to a thin plate lab, which may be of 26-gauge steel, plated and highly polished on its exposed surface, so as not to mar or adhere to the plastic laminations II.

The pressure plates [4 may be of spring steel i ds of an inch thick, and the spring plate l5 may be of spring steel %th of an' inch thick.

The pad members i3 provide sufficient resilience to compensate for unavoidable irregularities in-thickness of the cards l0 and plastic laminations I I, and surface irregularities in the pressure plates M.

It is to be understood that although for the purpose of explaining the invention a particular apparatus has been found suitable, and has been described in detail, modifications and variations in the particular apparatus and procedure described will be obvious to those skilled in the art, and the invention is to be limited only to the extent set forth in the appended claims.

I claim:

1. Apparatus for maintaining flat articles under pressure, comprising an assembly consisting of: a pair of thin, flexible sheet members adapted to fit against opposite sides of said articles and having their inner faces highly polished for smooth engagement with said articles;

engage the edges of said curved spring members to, maintain them in flat relation against said rigid plates independent of external force against said spring members.

s 2. Apparatus for maintaining flat articles under pressure, comprising an assembly consisting of: a pair of thin flexible sheet members adaptpress, another unit can be inserted. Furthered to fit against opposite sides of said articles more, a less expensive, unheated press can be and having their inner faces highly polished for smooth engagement with said articles; a pair of resilient pad members disposed exterior of and lying against said thin plate members; a pair of substantially flat rigid plate members positioned exterior of said pad members for compresssing them; a pair of outwardly bow'ed spring members exterior of said rigid plate members and adapted to flatten thereagainst by application of external force; and means detachably engageable with the end portions of said spring members at opposite ends oi the entire assembly for holding said end portions tozether and maintaining said spring members in flat relation against said rigid plates independent of external force against said spring members. 

